Batts has established himself as a proponent of curfews in his leadership stints in three cities. He hailed such an effort as successful in Long Beach, where he spent nearly 30 years, and pushed the idea in Oakland. There, the proposal was met by booing and hissing at a City Council meeting and rejected, and Batts resigned one week later lamenting his struggle to get a political support for that and other initiatives during his short stint in the Bay Area.

But in Baltimore, Batts found an ally in Scott, the 29-year-old councilman. Scott told The Sun on Tuesday that Batts had backed off the idea in the spring because Scott informed the commissioner that he was already working on the legislation and needed more time. The fact that Rawlings-Blake and Young are on board nearly ensures its passage here.

Some researchers say juvenile curfews do not work. Mike Males, a sociologist who researchers criminal justice issues, studied 400 citations given to 16- and 17-year-olds in Vernon, Connecticut and said there were only one or two cases where the teens were involved in a crime or misdemeanor. "It's a very effective tool to waste police time," Males told The Atlantic Cities.

In New Orleans, more than 2,500 youths were arrested in 2011 for violating that city's curfew law, one of the strictest in the nation with an 8 p.m. enforcement between Sunday and Thursday during the academic year, and 9 p.m. in the summer. A 2000 study of the city's curfew law found that it was ineffective because it didn't cover older adolescents and young adults, who often perpetrate crime, and excluded what are called the "afterschool hours" where minors are most likely to commit offenses, the New Orleans Times-Picayune reported.

Critics there said that the stepped-up enforcement of the law more recently was not changing the rate at which juveniles were prosecuted for delinquency, leading to questions about whether it had any real impact on youth crime.

At least one organization is questioning an earlier youth curfew in Baltimore: the city's police union. Robert F. Cherry, the union president, wrote on Twitter that he applauded Scott's effort, but said parents should look after their own children instead of leaving the job to officers.

"I said, 'Okay, I understand that. But which is more important, saving lives or being progressive?" Batts said at the meeting, to applause, according to the article.

Oakland's mayor, Jean Quan, said a curfew would be a hard sell to residents and would be hard to enforce with limited police resources.

Batts also supported so-called "gang injunctions," in which police can ask a judge to prohibit certain people from going to certain areas, and flexible work shifts for officers. When Batts resigned, he lamented that Oakland politicians didn't "let the chief be the chief."

"I can’t tell you how many community meetings I have gone to, and community people say, 'I want curfews. I want injunctions. I’m scared to death out here, I’m scared to death for my kids. We need to gain control of the city.' I’ll say, 'Why don’t you come down and say it at a council meeting?' They say, 'I’m scared to death to go down to a council meeting because there is no control at the council meetings.' So all you have out there at the council meeting are the loudest people yelling and screaming."

In Baltimore, Scott said an earlier curfew is common sense. "People are astonished that we allow kids to be out at 11 p.m., and especially at midnight," he said. And he is anticipating questions about whether it will be evenly enforced: Though he said he believes police will carry it out "across the board," he also said, "The sad reality is that if you go to Roland Park, you don't see kids out at 12 o'clock."